Acoustic wave devices with common ceramic substrate

ABSTRACT

An acoustic wave component is disclosed. The acoustic wave component can include a bulk acoustic wave resonator and a surface acoustic wave device. The bulk acoustic wave resonator can include a first portion of a ceramic substrate, a first piezoelectric layer positioned on the ceramic substrate, and electrodes positioned on opposing sides of the first piezoelectric layer. The surface acoustic wave device can include a second portion of the ceramic substrate, a second piezoelectric layer positioned on the ceramic substrate, and an interdigital transducer electrode on the second piezoelectric layer.

CROSS REFERENCE TO PRIORITY APPLICATIONS

This application claims the benefit of priority of U.S. ProvisionalPatent Application No. 62/785,906, filed Dec. 28, 2018 and titled “BULKACOUSTIC WAVE RESONATOR WITH SPINEL SUBSTRATE,” and U.S. ProvisionalPatent Application No. 62/785,958, filed Dec. 28, 2018 and titled“ACOUSTIC WAVE RESONATORS WITH COMMON SPINEL SUBSTRATE,” the disclosuresof each of which are hereby incorporated by reference in theirentireties herein.

BACKGROUND Technical Field

Embodiments of this disclosure relate to acoustic wave devices, forexample, bulk acoustic wave devices.

Description of Related Technology

Acoustic wave filters can be implemented in radio frequency electronicsystems. For instance, filters in a radio frequency front end of amobile phone can include one or more acoustic wave filters. A pluralityof acoustic wave filters can be arranged as a multiplexer. For instance,two acoustic wave filters can be arranged as a duplexer.

An acoustic wave filter can include a plurality of resonators arrangedto filter a radio frequency signal. Example acoustic wave filtersinclude surface acoustic wave (SAW) filters and bulk acoustic wave (BAW)filters. Example BAW resonators include film bulk acoustic waveresonators (FBARs) and solidly mounted resonators (SMRs). In BAWfilters, acoustic waves propagate in a bulk of a piezoelectric layer. ASAW filter can include an interdigital transductor electrode on apiezoelectric substrate and can generate a surface acoustic wave on asurface of the piezoelectric layer on which the interdigital transductorelectrode is disposed.

SUMMARY OF CERTAIN INVENTIVE ASPECTS

The innovations described in the claims each have several aspects, nosingle one of which is solely responsible for its desirable attributes.Without limiting the scope of the claims, some prominent features ofthis disclosure will now be briefly described.

In one aspect, a bulk acoustic wave resonator is disclosed. The bulkacoustic wave resonator includes a ceramic substrate, a piezoelectriclayer positioned on the ceramic substrate, and first and secondelectrodes positioned on opposing sides of the piezoelectric layer. Thebulk acoustic wave resonator also includes passivation layers thatincludes a first passivation layer and a second passivation layer. Thefirst passivation layer is positioned between the ceramic substrate andthe first electrode. The second electrode is positioned between thepiezoelectric layer and the second passivation layer. The bulk acousticwave resonator further includes a frame structure along an edge of anactive region of the bulk acoustic wave resonator.

In an embodiment, the ceramic substrate is a spinel substrate.

In an embodiment, the bulk acoustic wave resonator further includes anair cavity that is positioned between the ceramic substrate and thefirst electrode. The air cavity can be positioned over a surface of theceramic substrate closest to the piezoelectric layer. The air cavity isformed to have an acute angle with respect to the surface of the ceramicsubstrate.

In an embodiment, the bulk acoustic wave resonator is a film bulkacoustic wave resonator.

In an embodiment, the bulk acoustic wave resonator further includes anacoustic mirror positioned between the ceramic substrate and the firstelectrode.

In an embodiment, the bulk acoustic wave resonator further includes anacoustic mirror positioned on two sides of the ceramic substrate beneaththe frame structure.

In an embodiment, the frame structure includes at least one ofruthenium, molybdenum, tungsten, iridium, platinum, chromium, silicondioxide, silicon nitride, silicon oxynitride, aluminum oxide, or silicondioxide.

In an embodiment, the first passivation layer includes at least one ofsilicon dioxide, aluminum oxide, silicon carbide, aluminum nitride,silicon nitride, or silicon oxynitride.

In an embodiment, the ceramic substrate includes a planarized surfacefacing a center portion of the piezoelectric layer.

In an embodiment, the ceramic substrate is a polycrystalline ceramicsubstrate.

In an embodiment, at least a portion of the second electrode has adifferent thickness than the first electrode. The second electrode caninclude two different thicknesses.

In an embodiment, the frame structure includes a raised frame structure.

In an embodiment, the frame structure includes a raised frame structureand a recessed frame structure.

In an embodiment, the frame structure includes a first raised framelayer, and a second raised frame layer positioned between the firstelectrode and the piezoelectric layer.

In one aspect, an acoustic wave filter is disclosed. The acoustic wavefilter includes a bulk acoustic wave resonator. The bulk acoustic waveresonator includes a piezoelectric layer positioned on a ceramicsubstrate, first and second electrodes positioned on opposing sides ofthe piezoelectric layer, a first passivation layer positioned betweenthe ceramic substrate and the first electrode, a second passivationlayer positioned such that the second electrode is positioned betweenthe piezoelectric layer and the second passivation layer, a framestructure along an edge of an active region of the bulk acoustic waveresonator. The acoustic wave filter also include a plurality of acousticwave resonators. The bulk acoustic wave resonator and the plurality ofacoustic wave resonators together arranged to filter a radio frequencysignal.

In an embodiment, the ceramic substrate is a spinel substrate.

In an embodiment, the radio frequency signal has a frequency in a rangefrom 5 gigahertz to 10 gigahertz.

In one aspect a packaged module is disclosed. The packaged moduleincludes a packaging substrate, and an acoustic wave filter positionedon the packaging substrate. The acoustic wave filter is configured tofilter a radio frequency signal. The acoustic wave filter includes abulk acoustic wave resonator. The bulk acoustic wave resonator includesa ceramic substrate and a frame structure outside of a middle area of anactive region of the bulk acoustic wave resonator. The packaged modulealso includes a radio frequency component positioned on the packagingsubstrate. The acoustic wave filter and the radio frequency componentare enclosed within a common package.

In an embodiment, the ceramic substrate is a spinel substrate.

In an embodiment, the radio frequency component includes a poweramplifier.

In an embodiment, the radio frequency component includes a radiofrequency switch.

In an embodiment, the packaged module further includes a surfaceacoustic wave resonator on the ceramic substrate.

In one aspect, an acoustic wave component is disclosed. The acousticwave component includes a bulk acoustic wave resonator and a surfaceacoustic wave device. The bulk acoustic resonator includes a firstportion of a ceramic substrate, a first piezoelectric layer positionedon the ceramic substrate, and electrodes positioned on opposing sides ofthe first piezoelectric layer. The surface acoustic wave device includesa second portion of the ceramic substrate, a second piezoelectric layerpositioned on the ceramic substrate, and an interdigital transducerelectrode positioned on the second piezoelectric layer.

In an embodiment, the ceramic substrate is a spinel substrate.

In an embodiment, the bulk acoustic wave resonator includes a framestructure along an edge of an active region of the bulk acoustic waveresonator.

In an embodiment, wherein the bulk acoustic wave resonator includes apassivation layer positioned between the ceramic substrate and anelectrode of the electrodes that is closest to the ceramic substrate.

In an embodiment, the bulk acoustic wave resonator is a film bulkacoustic wave resonator.

In an embodiment, the bulk acoustic wave resonator includes an aircavity between the ceramic substrate and an electrode of the electrodes.The surface acoustic wave device can be disposed in the air cavity.

In an embodiment, the bulk acoustic wave resonator is positionedlaterally from the surface acoustic wave device.

In an embodiment, the acoustic wave component further includes a receivefilter and a transmit filter that are coupled to each other at a commonnode. The receive filter includes the surface acoustic wave device andthe transmit filter includes the bulk acoustic wave resonator.

In an embodiment, the transmit filter further includes another surfaceacoustic wave device that includes a third portion of the ceramicsubstrate. The transmit filter can further include a loop circuitconfigured to generate an anti-phase signal to a target signal at aparticular frequency. The loop circuit can include another surfaceacoustic wave device that includes a third portion of the ceramicsubstrate. The receive filter can further include a loop circuitconfigured to generate an anti-phase signal to a target signal at aparticular frequency. The loop circuit can include another surfaceacoustic wave resonator that includes a third portion of the ceramicsubstrate.

In one aspect, a multiplexer is disclosed. The multiplexer includes afirst filter that includes a bulk acoustic wave resonator and a secondfilter coupled to the first filter at a common node. The bulk acousticwave resonator includes a first portion of a ceramic substrate, a firstpiezoelectric layer positioned on the ceramic substrate, and electrodespositioned on opposing sides of the first piezoelectric layer. Thesecond filter includes a surface acoustic wave device. The surfaceacoustic wave device includes a second portion of the ceramic substrate,a second piezoelectric layer positioned on the ceramic substrate, and aninterdigital transducer electrode positioned on the second piezoelectriclayer.

In an embodiment, the ceramic substrate is a spinel substrate.

In one aspect, an acoustic wave component is disclosed. The acousticwave component includes a film bulk acoustic wave resonator and anothertype of acoustic wave resonator. The film bulk wave resonator includes afirst portion of a ceramic substrate, a piezoelectric layer positionedon the ceramic substrate, and electrodes positioned on opposing sides ofthe piezoelectric layer. The other type of acoustic wave resonatorincludes a second portion of the ceramic substrate.

In an embodiment, the ceramic substrate is a spinel substrate.

In an embodiment, the other type of acoustic wave resonator is a surfaceacoustic wave resonator.

In an embodiment, the other type of acoustic wave resonator is a solidlymounted resonator.

In an embodiment, the first portion of the ceramic substrate islaterally positioned from the second portion of the ceramic substrate.

In an embodiment, the first portion of the ceramic substratesubstantially overlaps with the second portion of the ceramic substrate.

In one aspect, an acoustic wave component is disclosed. The acousticwave component includes a bulk acoustic wave resonator that includes afirst portion of a glass substrate, a first piezoelectric layer on theglass substrate, and electrodes on opposing sides of the firstpiezoelectric layer the acoustic wave component also includes a surfaceacoustic wave device that includes a second portion of the glasssubstrate, a second piezoelectric layer on the glass substrate, and aninterdigital transducer electrode on the second piezoelectric layer.

In one embodiment, the glass substrate is a silicate glass substrate.

In one embodiment, the bulk acoustic wave resonator includes a framestructure along an edge of an active region of the bulk acoustic waveresonator.

In one embodiment, the bulk acoustic wave resonator includes apassivation layer between the glass substrate and an electrode of theelectrodes that is closest to the glass substrate.

In one embodiment, the bulk acoustic wave resonator is a film bulkacoustic wave resonator.

In one embodiment, the bulk acoustic wave resonator includes an aircavity between the glass substrate and an electrode of the electrodes.The surface acoustic wave device can be disposed in the air cavity.

In one embodiment, the bulk acoustic wave resonator is positionedlaterally from the surface acoustic wave device.

In one embodiment, the acoustic wave component further includes areceive filter and a transmit filter coupled to each other at a commonnode, the receive filter including the surface acoustic wave device andthe transmit filter including the bulk acoustic wave resonator. Thetransmit filter can further include another surface acoustic wave devicethat includes a third portion of the glass substrate. The transmitfilter can further include a loop circuit that is configured to generatean anti-phase signal to a target signal at a particular frequency. Theloop circuit can include another surface acoustic wave device thatincludes a third portion of the glass substrate. The receive filter canfurther include a loop circuit that is configured to generate ananti-phase signal to a target signal at a particular frequency. The loopcircuit can include another surface acoustic wave resonator thatincludes a third portion of the glass substrate.

In one aspect a multiplexer is disclosed. The multiplexer includes afirst filter that includes a bulk acoustic wave resonator. The bulkacoustic wave resonator includes a first portion of a glass substrate, afirst piezoelectric layer on the glass substrate, and electrodes onopposing sides of the first piezoelectric layer. The multiplexer alsoincludes a second filter that is coupled to the first filter at a commonnode. The second filter includes a surface acoustic wave device. Thesurface acoustic wave device includes a second portion of the glasssubstrate, a second piezoelectric layer on the glass substrate, and aninterdigital transducer electrode on the second piezoelectric layer.

In one embodiment, the glass substrate is a silicate glass substrate.

In one aspect, an acoustic wave component is disclosed. The acousticwave component includes a film bulk acoustic wave resonator thatincludes a first portion of a glass substrate, a piezoelectric layer onthe glass substrate, and electrodes on opposing sides of thepiezoelectric layer. The acoustic wave component also includes anothertype of acoustic wave resonator including a second portion of the glasssubstrate.

In one embodiment, the glass substrate is a silicate glass substrate.

In one embodiment, the other type of acoustic wave resonator is asurface acoustic wave resonator.

In one embodiment, the other type of acoustic wave resonator is asolidly mounted resonator.

In one embodiment, the first portion of the glass substrate is laterallypositioned from the second portion of the glass substrate.

In one embodiment, the first portion of the glass substratesubstantially overlaps with the second portion of the glass substrate.

In one aspect, a bulk acoustic wave resonator is disclosed. The bulkacoustic wave resonator includes a spinel substrate, a piezoelectriclayer on the spinel substrate, first and second electrodes on opposingsides of the piezoelectric layer, passivation layers including a firstpassivation layer and a second passivation layer, and a frame structurealong an edge of an active region of the bulk acoustic wave resonator.The first passivation layer is positioned between the spinel substrateand the first electrode. The second electrode is positioned between thepiezoelectric layer and the second passivation layer.

In an embodiment, the bulk acoustic wave resonator further includes anair cavity that is positioned between the spinel substrate and the firstelectrode. The air cavity can be positioned over a surface of the spinellayer closest to the piezoelectric layer. The air cavity can be formedto have an acute angle with respect to the surface of the spinelsubstrate.

In an embodiment, the bulk acoustic wave resonator is a film bulkacoustic wave resonator.

In an embodiment, the bulk acoustic wave resonator further includes anacoustic mirror that is positioned between the spinel substrate and thefirst electrode.

In an embodiment, the bulk acoustic wave resonator further includes anacoustic mirror that is positioned on two sides of the spinel substratebeneath the frame structure.

In an embodiment, the frame structure includes at least one ofruthenium, molybdenum, or silicon dioxide.

In an embodiment, the first passivation layer includes silicon dioxide.

In an embodiment, the spinel substrate includes a planarized surfacefacing a center portion of the piezoelectric layer.

In an embodiment, the spinel substrate is a polycrystalline spinelsubstrate.

In an embodiment, at least a portion of the second electrode has adifferent thickness than the first electrode. The second electrode caninclude two different thicknesses.

In an embodiment, an acoustic wave filter is disclosed. The acousticwave filter can include acoustic wave resonators that are arranged tofilter a radio frequency signal. The acoustic wave resonators caninclude a bulk acoustic wave resonator of any of the above embodiments.A front end module that includes the acoustic wave filter, additionalcircuitry, and a package enclosing the surface acoustic wave filter andthe additional circuitry is disclosed. The additional circuitry caninclude a multi-throw radio frequency switch. The additional circuitrycan include a power amplifier. A wireless communication device thatincludes the antenna and the acoustic wave filter is disclosed. Theacoustic wave filter can be arranged to filter a radio frequency signalassociated with the antenna.

In one aspect, a method of manufacturing a bulk acoustic wave resonatoris disclosed. The method includes depositing a sacrificial layer over aspinel substrate, and forming a first electrode of a bulk acoustic waveresonator over the sacrificial layer. The method also includes forming apiezoelectric layer and a second electrode of the bulk acoustic waveresonator over the first electrode such that the piezoelectric layer ispositioned between the first electrode and the second electrode. Themethod further includes removing sacrificial material of the sacrificiallayer between the first electrode and piezoelectric layer and the spinelsubstrate to form an air gap.

In an embodiment, the bulk acoustic wave resonator further includessmoothing a surface of the spinel substrate prior to the depositing.

In an embodiment, the bulk acoustic wave resonator further includesperforming chemical mechanical polishing on a surface of the spinelsubstrate prior to the depositing

In an embodiment, the forming the first electrode is performed such thatthe first electrode is in physical contact with a passivation layer.

In an embodiment, the bulk acoustic wave resonator further includesdepositing a passivation layer over the second electrode.

In an embodiment, the bulk acoustic wave resonator is a film bulkacoustic wave resonator.

In an embodiment, the sacrificial layer is deposited directly over thespinel substrate.

The method can further include forming a frame structure of the bulkacoustic wave resonator.

In one aspect, a packaged module is disclosed. The packaged moduleincludes a packaging substrate and an acoustic wave filter positioned onthe packaging substrate. The acoustic wave filter is configured tofilter a radio frequency signal. The acoustic wave filter includes abulk acoustic wave resonator. The bulk acoustic wave resonator includesa spinel substrate and a frame structure outside of a middle area of anactive region of the bulk acoustic wave resonator. The packaged modulealso includes a radio frequency component positioned on the packagingsubstrate. The acoustic wave filter and the radio frequency componentare enclosed within a common package.

In an embodiment the radio frequency component includes a poweramplifier.

In an embodiment, the radio frequency component includes a radiofrequency switch.

In an embodiment, the packaged module further includes a surfaceacoustic wave resonator on the spinel substrate.

In an embodiment, the bulk acoustic wave resonator further includes anysuitable one or more of the above features.

In one aspect, a bulk acoustic wave resonator is disclosed. The bulkacoustic wave resonator can include a spinel substrate, a piezoelectriclayer on the spinel substrate, first and second electrodes on opposingsides of the piezoelectric layer, and passivation layers that include afirst passivation layer and a second passivation layer. The firstpassivation layer is positioned between the spinel substrate and thefirst electrode. The second electrode is positioned between thepiezoelectric layer and the second passivation layer. The bulk acousticwave resonator also includes a frame structure along an edge of anactive region of the bulk acoustic wave resonator.

In an embodiment, the bulk acoustic wave resonator further includes anair cavity positioned between the spinel substrate and the firstelectrode. The air cavity can be over a surface of the spinel layerclosest to the piezoelectric layer.

In an embodiment, the air cavity is formed to have an acute angle withrespect to the surface of the spinel substrate.

In an embodiment, the bulk acoustic wave resonator is a film bulkacoustic wave resonator.

In an embodiment, the bulk acoustic wave resonator further includes anacoustic mirror positioned between the spinel substrate and the firstelectrode.

In an embodiment, the bulk acoustic wave resonator further includes anacoustic mirror positioned on two sides of the spinel substrate beneaththe frame structure.

In an embodiment, the frame structure includes at least one ofruthenium, molybdenum, or silicon dioxide.

In an embodiment, the first passivation layer includes silicon dioxide.

In an embodiment, the spinel substrate includes a planarized surfacefacing a center portion of the piezoelectric layer.

In an embodiment, the spinel substrate is a polycrystalline spinelsubstrate.

In an embodiment, at least a portion of the second electrode has adifferent thickness than the first electrode.

In an embodiment, the second electrode includes two differentthicknesses.

In an embodiment, an acoustic wave filter that includes acoustic waveresonators arranged to filter a radio frequency signal is disclosed. Theacoustic wave resonators can include a bulk acoustic wave resonator ofany of the above embodiments. A front end module can include theacoustic wave filter, additional circuitry, and a package enclosing thesurface acoustic wave filter and the additional circuitry. Theadditional circuitry can include a multi-throw radio frequency switch.The additional circuitry can include a power amplifier. In anembodiment, a wireless communication device that includes the antennaand then acoustic wave filter is disclosed. The acoustic wave filter canbe arranged to filter a radio frequency signal associated with theantenna.

In one aspect, a method of manufacturing a bulk acoustic wave resonatoris disclosed. The method includes depositing a sacrificial layer over aspinel substrate, forming a first electrode of a bulk acoustic waveresonator positioned over the sacrificial layer, forming a piezoelectriclayer and a second electrode of the bulk acoustic wave resonatorpositioned over the first electrode such that the piezoelectric layer ispositioned between the first electrode and the second electrode, andremoving sacrificial material of the sacrificial layer positionedbetween the first electrode and piezoelectric layer and the spinelsubstrate to form an air gap.

In an embodiment, the method further includes smoothing a surface of thespinel substrate prior to the depositing.

In an embodiment, the method further includes performing chemicalmechanical polishing on a surface of the spinel substrate prior to thedepositing

In an embodiment, the forming the first electrode is performed such thatthe first electrode is in physical contact with a passivation layer.

In an embodiment, the method further includes depositing a passivationlayer over the second electrode.

In an embodiment, the bulk acoustic wave resonator is a film bulkacoustic wave resonator.

In an embodiment, the sacrificial layer is deposited directly over thespinel substrate.

In an embodiment, the method further includes forming a frame structureof the bulk acoustic wave resonator.

In one aspect, an acoustic wave component is disclosed. The acousticwave component includes a bulk acoustic wave resonator and a surfaceacoustic wave resonator. The bulk acoustic wave resonator includes afirst portion of a spinel substrate, a first piezoelectric layerpositioned on the spinel substrate, and electrodes positioned onopposing sides of the first piezoelectric layer. The surface acousticwave resonator includes a second portion of the spinel substrate, asecond piezoelectric layer positioned on the spinel substrate, and aninterdigital transducer electrode positioned on the second piezoelectriclayer.

In an embodiment, the bulk acoustic wave resonator includes a framestructure along an edge of an active region of the bulk acoustic waveresonator.

In an embodiment, the bulk acoustic wave resonator includes apassivation layer between the spinel substrate and an electrode of theelectrodes that is closest to the spinel substrate.

In an embodiment, the bulk acoustic wave resonator is a film bulkacoustic wave resonator.

In an embodiment, the bulk acoustic wave resonator includes an aircavity between the spinel substrate and an electrode of the electrodes,the air cavity being over a surface of the spinel layer closest to theelectrode.

In an embodiment, the acoustic wave component further includes a receivefilter and a transmit filter that are coupled to each other at a commonnode. The receive filter can include the surface acoustic wave resonatorand the transmit filter including the bulk acoustic wave resonator.

In an embodiment, the transmit filter further includes another surfaceacoustic wave resonator that includes a third portion of the spinelsubstrate.

In an embodiment, the transmit filter further includes a loop circuit.The loop circuit can include another surface acoustic wave resonatorthat includes a third portion of the spinel substrate.

In an embodiment, the receive filter further includes a loop circuit.The loop circuit can include another surface acoustic wave resonatorthat includes a third portion of the spinel substrate.

In an embodiment, the bulk acoustic wave resonator further includes anysuitable one or more of the above features.

In one aspect, an acoustic wave component is disclosed. The acousticwave component includes a film bulk acoustic wave resonator and anothertype pf acoustic wave resonator. The film bulk acoustic wave componentincludes a first portion of a spinel substrate, a piezoelectric layerpositioned on the spinel substrate, and electrodes positioned onopposing sides of the piezoelectric layer. The other type of acousticwave resonator includes a second portion of the spinel substrate.

In an embodiment, the other type of acoustic wave resonator is a surfaceacoustic wave resonator.

In an embodiment, the other type of acoustic wave resonator is a solidlymounted resonator.

In an embodiment, the acoustic wave component further includes anysuitable one or more if the above features.

In one aspect, a multiplexer is disclosed. The multiplexer includes areceive filter that is coupled to a common node and a transmit filterthat is coupled to the common node. The receive filter includes asurface acoustic wave resonator. The surface acoustic wave resonatorincludes a first portion of a spinel substrate. The transmit filtertransmit filter includes a bulk acoustic wave resonator. The bulkacoustic wave resonator includes a second portion of the spinelsubstrate.

In an embodiment, the multiplexer is a duplexer.

In an embodiment, the bulk acoustic wave resonator further includes oneor more suitable features of the above embodiments.

In an embodiment, the multiplexer further includes one or more suitablefeatures of the above embodiments.

In one aspect, a method of manufacturing an acoustic wave component isdisclosed. The method includes forming a bulk acoustic wave resonator ona spinel substrate, forming a different type of acoustic wave resonatoron the spinel substrate.

In an embodiment, the different type of resonator is a surface acousticwave resonator.

In an embodiment, the method further comprising electrically connectingthe bulk acoustic wave resonator and the different type of resonatorsuch that they are included in a band pass filter. The filter is atransmit filter, and the different type of acoustic wave resonator iscoupled between the bulk acoustic wave resonator and an output port ofthe transmit filter.

In one aspect, a packaged module is disclosed. The packaged moduleincludes a packaging substrate, an acoustic wave filter positioned onthe packaging substrate. The acoustic wave filter is configured tofilter a radio frequency signal. The acoustic wave filter includes abulk acoustic wave resonator. The bulk acoustic wave resonator includesa spinel substrate and a frame structure outside of a middle area of anactive region of the bulk acoustic wave resonator. The packaged modulealso includes a radio frequency component positioned on the packagingsubstrate. The acoustic wave filter and the radio frequency componentare enclosed within a common package.

In an embodiment, the radio frequency component includes a poweramplifier.

In an embodiment, the radio frequency component includes a radiofrequency switch.

In an embodiment, the packaged module further includes a surfaceacoustic wave resonator on the spinel substrate.

In an embodiment, the bulk acoustic wave resonator further includes oneor more suitable features of above embodiments.

For purposes of summarizing the disclosure, certain aspects, advantagesand novel features of the innovations have been described herein. It isto be understood that not necessarily all such advantages may beachieved in accordance with any particular embodiment. Thus, theinnovations may be embodied or carried out in a manner that achieves oroptimizes one advantage or group of advantages as taught herein withoutnecessarily achieving other advantages as may be taught or suggestedherein.

The present disclosure relates to U.S. patent application Ser. No.______ [Attorney Docket SKYWRKS.902A1], titled “BULK ACOUSTIC WAVERESONATOR WITH CERAMIC SUBSTRATE,” filed on even date herewith, theentire disclosure of which is hereby incorporated by reference herein.The present disclosure relates to U.S. Patent Application No. [AttorneyDocket SKYWRKS.902A3], titled “ACOUSTIC WAVE DEVICES WITH COMMON GLASSSUBSTRATE,” filed on even date herewith, the entire disclosure of whichis hereby incorporated by reference herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of this disclosure will now be described, by way ofnon-limiting example, with reference to the accompanying drawings.

FIGS. 1A to 1E are a cross sectional views illustrating a process ofmanufacturing a bulk acoustic wave resonator according to an embodiment.

FIG. 1A illustrates a cross section of a device including a spinelsubstrate and a sacrificial layer.

FIG. 1B illustrates a cross section of a device including a spinelsubstrate and an island pattern for the sacrificial layer.

FIG. 1C illustrates a cross section of a device including a firstelectrode over the island pattern.

FIG. 1D illustrates a cross section with a piezoelectric layer and asecond electrode over the first electrode.

FIG. 1E is a cross sectional view of a bulk acoustic wave device on aspinel substrate according to an embodiment.

FIG. 1F is a cross sectional view of a bulk acoustic wave resonatordevice on a ceramic substrate according to an embodiment.

FIG. 1G is a cross sectional view of a bulk acoustic wave resonatordevice on a glass substrate according to an embodiment.

FIG. 1H is a cross sectional view of a bulk acoustic wave resonatordevice on a spinel substrate according to another embodiment.

FIG. 1I is a cross sectional view of a bulk acoustic wave resonatordevice on a ceramic substrate according to another embodiment.

FIG. 1J is a cross sectional view of a bulk acoustic wave resonatordevice on a glass substrate according to another embodiment

FIG. 2 is a graph that compares quality factor and magnitude for anacoustic wave resonator having a spinel substrate according to anembodiment with a baseline bulk acoustic wave resonator.

FIG. 3 is a cross sectional view of a bulk acoustic wave resonatoraccording to another embodiment.

FIG. 4 is a cross sectional view of a bulk acoustic wave resonatoraccording to another embodiment.

FIG. 5A is a cross sectional view of a bulk acoustic wave resonatoraccording to another embodiment.

FIG. 5B is a cross sectional view of a bulk acoustic wave resonatoraccording to another embodiment.

FIG. 6A is a cross sectional view of a bulk acoustic wave resonator anda surface acoustic wave device on a common spinel substrate according toan embodiment.

FIG. 6B is a cross sectional view of a bulk acoustic wave resonator andsurface acoustic wave device on a common spinel substrate according toanother embodiment.

FIG. 7A is a cross sectional view of bulk acoustic wave and surfaceacoustic wave devices on a spinel substrate according to an embodiment.

FIG. 7B is a schematic diagram illustrating bulk acoustic wave andsurface acoustic wave devices of a duplexer according to an embodiment.

FIG. 8 is a schematic diagram illustrating a duplexer with loop circuitsand acoustic wave devices according to an embodiment.

FIG. 9 is a schematic diagram of a transmit filter including a loopcircuit that includes acoustic wave devices according to an embodiment.

FIG. 10 is a schematic diagram of a receive filter including a loopcircuit that includes acoustic wave devices according to an embodiment.

FIG. 11 is a schematic diagram of a radio frequency module that includesan acoustic wave component according to an embodiment.

FIG. 12 is a schematic diagram of a radio frequency module that includesan acoustic wave filters according to an embodiment.

FIG. 13A is a schematic block diagram of a wireless communication devicethat includes a filter in accordance with one or more embodiments.

FIG. 13B is a schematic block diagram of another wireless communicationdevice that includes a filter in accordance with one or moreembodiments.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

The following description of certain embodiments presents variousdescriptions of specific embodiments. However, the innovations describedherein can be embodied in a multitude of different ways, for example, asdefined and covered by the claims. In this description, reference ismade to the drawings, where like reference numerals can indicateidentical or functionally similar elements. It will be understood thatelements illustrated in the figures are not necessarily drawn to scale.Moreover, it will be understood that certain embodiments can includemore elements than illustrated in a drawing and/or a subset of theelements illustrated in a drawing. Further, some embodiments canincorporate any suitable combination of features from two or moredrawings.

Various bulk acoustic wave (BAW) resonators are formed on siliconwafers. When a silicon wafer is used as a substrate of BAW resonator forradio frequency (RF) filter fabrication, high-resistivity silicon (HRS)can be used to implement a relatively high performance resonator. TheHRS substrate can blocking energy leakage into the substrate. In forminga BAW structure that is made on the wafer and an air cavity that allowsfree vibration of the BAW resonator, the substrate can be protected byusing a silicon dioxide (SiO₂) film for protecting the substrate in theoperation of removing sacrificial layer and the like. In order to form asilicon dioxide film, a deposition method such as chemical vapordeposition (CVD) and/or physical vapor deposition (PVD) to oxidize thesilicon substrate can be used. During such a process, electrons andholes can be charged up at the interface between the oxide and thesubstrate. These mobile electrons and holes can cause the resistance ofan HRS substrate to be reduced. This can adversely affect thecharacteristics of a BAW resonator, such as the quality factor (Q) valueand/or the BAW filter characteristic.

A BAW resonator can be fabricated directly on the silicon interface toavoid the mobile electrons and/or holes generated at the interfacebetween oxide and silicon. In this case, unique processes and chemicalscan be used to realize BAW structure. Alternatively or additionally, atrap layer can be formed between oxide and silicon to reduce and/oreliminate mobility.

Aspects of this disclosure relate to a BAW resonator on a spinelsubstrate. The spinel substrate can be a polycrystalline spinelsubstrate. The polycrystalline spinel substrate can be a magnesiumaluminate (MgAl₂O₄) spinel substrate. Such a BAW resonator can have goodRF performance and mechanical processing characteristics. Gas thatremoves the sacrificial layer may not etch the spinel substrate at all.Accordingly, a sacrificial layer can be formed directly over the spinelsubstrate. As such, a BAW resonator on a spinel substrate can providedesirable RF characteristics and also to simplify a manufacturingprocess.

There are a number of advantages associated with BAW resonators on aspinel substrate. For example, there can be a relatively low tangentloss at radio frequencies. A BAW resonator on a spinel substrate canprovide better mechanical strength than a similar BAW resonator on anHRS substrate. A BAW resonator on a spinel substrate can have goodprocessability during processing, such as dicing. BAW resonators onspinel substrates can reduce and/or eliminate mobilized electrons andholes that can be present in other BAW resonators. BAW resonators onspinel substrates can reduce and/or eliminate resistivity reduction ofthe substrate by thermal donors of oxygen impurity. Moreover, a BAWresonator and a different type of acoustic wave resonator can beimplemented on a common spinel substrate.

A spinel substrate is an example of a ceramic substrate. Any suitableprinciples and advantages of embodiments that include a spinel substratecan be implemented by any suitable ceramic substrate. For example, anacoustic wave device and/or acoustic wave component and/or acoustic wavefilter can be implemented with a ceramic substrate in accordance withany suitable principles and advantages disclosed herein. Moreover, anysuitable principles and advantages of embodiments that include a spinelsubstrate can be implemented by a glass substrate. For example, anacoustic wave device and/or acoustic wave component and/or acoustic wavefilter can be implemented with a glass substrate in accordance with anysuitable principles and advantages disclosed herein.

The acoustic wave resonators disclosed herein can be implemented inacoustic wave filters. The acoustic wave filters can be band passfilters arranged to pass a radio frequency band and attenuatefrequencies outside of the radio frequency band. Two or more acousticwave filters can be coupled together at a common node and arranged as amultiplexer, such as a duplexer.

Acoustic wave filters can filter radio frequency (RF) signals in avariety of applications, such as in an RF front end of a mobile phone.An acoustic wave filter can be implemented with surface acoustic wave(SAW) devices and/or BAW resonators. SAW devices include SAW resonators,SAW delay lines, and multi-mode SAW (MMS) filters (e.g., double mode SAW(DMS) filters).

FIGS. 1A to 1E are example cross-sectional views illustrating a processof manufacturing a bulk acoustic wave resonator on a spinel substrateaccording to an embodiment. The BAW resonator can be included in a bandpass filter, for example.

FIG. 1A is a cross sectional view of a spinel substrate 102 with asacrificial layer 104 on the spinel substrate 102. The spinel substrate102 can be a polycrystalline spinel substrate (e.g., a magnesiumaluminate (MgAl₂O₄) polycrystalline spinel substrate). The spinelsubstrate 102 can have relatively high resistivity. In an illustrativeexample, the spinel substrate 102 may be formed by combining twodifferent materials. For example, spinel may be formed by combiningalumina and magnesia together. In some embodiments, the spinel materialmay be formed from a high-purity powder. The powder may then be formed,sintered, and machined. For example, one or more surfaces of the spinelsubstrate 102, such as a top and bottom surfaces, may be smoothed and/orplanarized using chemical mechanical polishing (CMP). With suchsmoothing and/or planarization, the spinel substrate 102 can have asurface roughness of less than 1 nanometer (nm). As an example, thespinel substrate may be formed to have a 0.4 nm surface roughness (Ra).As another example, mechanical polishing may be used to achieve asurface roughness of less than 3 nm, such as a roughness of 2 nm orless. For instance, the spinel substrate 102 can be a polycrystallinespinel substrate with a surface roughness in a range from about 0.1 nmto 2 nm in certain applications. A surface that has been planarizedusing mechanical polishing procedures may be referred to as a planarizedsurface once the surface is adequately polished according to apredetermined specification (e.g., surface roughness, uniformity acrossthe substrate, sufficiently uniform thickness of the substrate acrossthe length of the substrate, etc.).

The spinel substrate 102 may be formed to have certain materialproperties within a predetermined range. For example, the spinelsubstrate 102 may have a density within a range of 3.4 to 3.7 grams percentimeters cubed, such that the density approximates 3.6 grams percentimeter. As another example, the spinel substrate 102 can have acoefficient of thermal expansion of roughly 5.9 ppm/K and a thermalconductivity of roughly 18.0 W/mK.

The sacrificial layer 104 can be deposited directly on the spinelsubstrate 102 as illustrated. The sacrificial layer 104 can be removedat a later stage of manufacture. By removing the sacrificial layer 104,an air cavity can for formed, for example, as will be described below inconnection with FIG. 1E. The sacrificial layer 104 can be formed of anysuitable sacrificial material, such as amorphous silicon or polysilicon.The sacrificial layer 104 may be formed in direct contact with at leasta portion of spinel substrate 102. The sacrificial layer 104 may besubstantially parallel with the spinel substrate 102 with respect to atleast one surface of each.

The structure shown in FIG. 1A becomes part of a BAW resonator, and morespecifically a film bulk acoustic wave resonator (FBAR), as disclosed inconnection with FIGS. 1B to 1E. Other types of acoustic wave resonators,such as SAW resonators, boundary acoustic wave resonators, SMRs, and/orLamb wave resonators, can also be formed on the spinel substrate 102. Incertain embodiments, the spinel substrate may be of a substantiallyuniform thickness. In some other embodiments, the spinel substrate maybe of various thicknesses. For example, in an embodiment where thespinel substrate is used as a common substrate for multiple acousticwave filters, various thicknesses may correspond to the footprint fordifferent acoustic wave filters that are formed on the spinel substrate.

In some embodiments (not illustrated in FIGS. 1A to 1E), an upperportion of the spinel substrate 102 may be etched away. For example, thespinel substrate 102 may be etched in one or more portions near thecenter of the footprint of the filter to form a cavity. In suchembodiments, a sacrificial layer may be deposited within the one or morecavities of spinel substrate 102. In addition, a sacrificial layer 104may be formed above and within the one or more cavities of spinelsubstrate 102. In some examples, the sacrificial layer 104 may be formedof different materials, such that the layers may be removed at differentstages. For example, a sacrificial layer of one material may be formedin the one or more cavities of spinel substrate 102, whereas anothersacrificial layer 104 of another material may be formed above the planarsurface of spinel substrate 102 and the underlying sacrificial layer. Insome embodiments, the sacrificial layer 104 may not be used. In anexample, a bulk acoustic wave resonator may be a solidly mountedresonator (SMR) with an acoustic mirror. Certain SMRs can be formedwithout the sacrificial layer 104. In some other embodiments, anacoustic mirror may be used in conjunction with a sacrificial layer 104,such that an air cavity may be formed above or below the acoustic mirrorin a BAW-SMR device.

FIG. 1B is a cross sectional view that illustrates that sacrificialmaterial can be patterned over the spinel substrate 102 to form apatterned sacrificial layer 122. As shown in FIG. 1B, the sacrificiallayer 122 has been etched into an island pattern. The island pattern mayhave angled edges as shown or may have sharper edges. For example, theformation of the slopes for the island pattern on one or both sides maybe controlled to make less than a 90 degree angle with respect to thetop surface of the spinel substrate 102, for example, as shown. Theisland pattern of the patterned sacrificial layer 122 may be covered bya passivation layer 126 as illustrated.

FIG. 1C is a cross sectional view illustrating an electrode 128 disposedover the spinel substrate 102 and the patterned sacrificial layer 122.The electrode 128 may be of any suitable conductive material. Asillustrated, the first electrode 128 extends across a portion of thepatterned sacrificial layer 122. The first electrode 128 may have one ormore angled edges. For example, the slope of one or more edges of theelectrode may be formed to approximate the slope formed by the patternedsacrificial layer 122 with respect to the planar surface of the spinelsubstrate 102. A layer 129 may be disposed between electrode 128 and anupper surface of spinel substrate 102 and the patterned sacrificiallayer 122. Layer 129 may be formed to extend along all or at least aportion of electrode 128. In some embodiments, layer 129 may extendbeyond electrode 128, such that there is only some overlap with theelectrode 128.

FIG. 1D is a cross sectional view illustrating a piezoelectric layer 150and a second electrode 152 over the first electrode 128. Thepiezoelectric layer 150 is disposed between the first electrode 128 andthe second electrode 152. The piezoelectric layer 150 can be an aluminumnitride (AlN) layer or any other suitable piezoelectric layer. An activeregion or active domain of a bulk acoustic wave resonator can be definedby the portion of the piezoelectric layer 150 that overlaps with boththe first electrode 128 and the second electrode 152 over an air cavity144. In the embodiment shown in FIG. 1D, the first and second electrodes128 and 152, respectively, overlap for a significant portion of thepiezoelectric layer 150.

FIG. 1E is a cross sectional view of a bulk acoustic wave resonator 160.As illustrated, the bulk acoustic wave resonator 160 includes thepiezoelectric layer 150, the first electrode 128, the second electrode152, a frame structure (e.g., raised frame structure 175), a spinelsubstrate 102, an air cavity 144, and electrical connection layers thatinclude a first layer 176 and a second layer 178. A layer 129 may beincluded below the first electrode 128, for example, as described above.The first layer 176 can include one or more of ruthenium, molybdenum, orsilicon dioxide. The second layer 178 can include titanium and/orcopper. The patterned sacrificial layer 122 from FIGS. 1B to 1D can beremoved to form the air cavity 144 shown in FIG. 1E.

The bulk acoustic wave resonator 160 of FIG. 1E is an FBAR. The aircavity 144 is included between the first electrode 128 and the spinelsubstrate 102. In addition, one or more passivation layers can beincluded between the first electrode 128 and the spinel substrate 102.For example, the passivation layer 126 is positioned between the firstelectrode 128 and the spinel substrate in FIG. 1E. The passivation layercan include at least one of silicon dioxide, aluminum oxide, siliconcarbide, aluminum nitride, silicon nitride, or silicon oxynitride. Theillustrated air cavity 144 is defined at least in part by the geometryof the first electrode 128 and the spinel substrate 102. The air cavity144 may be formed by removing the patterned sacrificial layer 122deposited on the spinel substrate 102.

Bulk acoustic wave resonators can include a frame structure. The framestructure can include a raised frame structure, a recessed framestructure, or a raised frame structure and a recessed frame structure.An example frame structure that includes a raised frame structure isshown in FIGS. 1E-1G. An example frame structure that includes a raisedframe structure and a recessed frame structure is illustrated in FIGS.1H-1J.

The bulk acoustic wave resonator 160 includes an active region where thefirst and second electrodes 128 and 152 overlap in a directionsubstantially normal to an upper surface of the spinel substrate 102.The bulk acoustic wave resonator 160 of FIG. 1E includes a raised framezone around a perimeter of the active region of the bulk acoustic waveresonator 160. The raised frame zone can be referred to as a border ringin certain instances. The raised frame structure 175 is in the raisedframe zone. The raised frame structure 175 is outside of a middle areaof the active region of the bulk acoustic wave device. The raised framestructure 175 is in the raised frame zone and extends above the firstand second electrodes 128 and 152, respectively, and piezoelectric layer150. The raised frame structure 175 can include at least one ofruthenium, molybdenum tungsten, iridium, platinum, chromium, silicondioxide, silicon nitride, silicon oxynitride, aluminum oxide, or siliconcarbide

The raised frame structure 175 can be a relatively high densitymaterial. For instance, the second raised frame layer 24 can includemolybdenum (Mo), tungsten (W), ruthenium (Ru), the like, or any suitablealloy thereof. The raised frame structure 175 can be a metal layer.Alternatively, the raised frame structure 175 can be a suitablenon-metal material with a relatively high density. The density of theraised frame structure 175 can be similar or heavier than the density ofthe second electrode 152. The raised frame structure 175 can have arelatively high acoustic impedance. The raised frame structure 175 canreduce a transverse spurious mode. The raised frame structure 175 canblock lateral energy leakage from the active domain of the bulk acousticwave resonator 160. This can increase the quality factor (Q) of the bulkacoustic wave resonator 160. The raised frame structure 175 can beannular in plan view. In some embodiments, a bulk acoustic waveresonator 160 may include two raised frame domains.

One or more passivation layers 174 can be included over the secondelectrode 152. For instance, a silicon dioxide passivation layer can beincluded as the passivation layer 174 over the second electrode 152. Thepassivation layer 174 can be formed with different thicknesses indifferent regions of the bulk acoustic wave resonator 160. In addition,the first electrode 128 and/or the second electrode 152 may be formed tohave different thicknesses in different regions of the bulk acousticwave resonator 160. For example, as shown in FIG. 1E, the secondelectrode 152 is thinner in various portions of the bulk acoustic waveresonator 160. In certain embodiments, the second electrode 152 of thebulk acoustic wave resonator 160 may include different material than thefirst electrode 128 of the bulk acoustic wave resonator 160. The secondelectrode 152 has different thicknesses in different regions.

The bulk acoustic wave resonator 160 can have a relatively high resonantfrequency. A combination of material of the piezoelectric layer 150 andthickness of piezoelectric layer 150 can impact resonant frequency. Witha thinner piezoelectric layer 150, the resonant frequency can be higher.Aluminum nitride can be a suitable material for achieving a relativelyhigh resonant frequency.

Bulk acoustic wave resonators disclosed herein can have a piezoelectriclayer 150 with a material and thickness combination that can achieve aresonant frequency of up to about 13 GHz with desirable electricalcharacteristics (e.g., desirable Q values). Such BAW resonators can havea ceramic substrate, a magnesium aluminate spinel substrate, or a glasssubstrate. BAW resonators disclosed herein can filter radio frequencysignals in an operating band in a range from 3.5 GHz to 13 GHz. Forexample, a piezoelectric layer 150 of aluminum nitride can have athickness of about 0.4 μm for filtering frequency signals in anoperating band of about 5 GHz. For example, a piezoelectric layer 150 ofaluminum nitride can have a thickness of about 0.2 μm for filteringfrequency signals in an operating band of about 10 GHz. For example, thepiezoelectric layer 150 can have a thickness of about 0.1 μm forfiltering frequency signals in an operating band in a range of 12 GHz to13 GHz.

Although FIGS. 1A to 1E illustrate cross sectional views ofmanufacturing an FBAR, any suitable principles and advantages disclosedherein can be applied to other suitable acoustic wave resonators, suchas a solidly mounted resonator (SMR) or a Lamb wave resonator.

As discussed above, the bulk acoustic wave resonator 160 includes aspinel base substrate 102. The spinel substrate 102 can improve thequality factor (Q) relative to using a different substrate.

A spinel substrate is an example of a ceramic substrate. FIG. 1F is across sectional view of a bulk acoustic wave resonator 161. The bulkacoustic wave resonator 161 is generally similar to the bulk acousticwave resonator 160 illustrated in FIG. 1E, except that the bulk acousticwave resonator 161 includes a ceramic substrate 103 in place of thespinel substrate 102 of the bulk acoustic wave resonator 160. Theceramic substrate 103 can include, for example, polycrystalline spinel(e.g., MgAl₂O₄ which can be referred to as a magnesium aluminatespinel), co-fired ceramic, sapphire (Al₂O₃), silicon carbide (SiC), orpolycrystalline aluminum nitride (AlN). The ceramic substrate 130 canhave higher acoustic impedance than an acoustic impedance of thepiezoelectric layer 150. Some ceramic materials, such as Al₂O₃ and SiC,can have better thermal conductivity, power handling, and ruggednessthan other materials. A manufacturing process similar to thatillustrated in FIGS. 1A-1E can be applied to manufacturing the bulk waveresonator 161 illustrated in FIG. 1F. Moreover, any suitable principlesand advantages of devices, components, and filters disclosed herein thatinclude a spinel substrate can be applied to devices, components, andfilters that includes a ceramic substrate.

FIG. 1G is a cross sectional view of a bulk acoustic wave resonator 162.The bulk acoustic wave resonator 162 is generally similar to the bulkacoustic wave resonators 160, 161 illustrated in FIGS. 1E and 1F, exceptthat the bulk acoustic wave resonator 162 includes a glass substrate 105in place of the spinel substrate 102 of the bulk acoustic wave resonator160 and in place of the ceramic substrate 103 of the bulk acoustic waveresonator 161. The glass substrate 105 includes a non-crystallineamorphous solid. The glass substrate 105 can include a silicate glass,such as fused quartz glass, lead glass, borosilicate glass, soda-limesilicate glass, aluminosilicate glass, or germanium-oxide glass. Amanufacturing process similar to that illustrated in FIGS. 1A-1E can beapplied to manufacturing the bulk wave resonator 162 illustrated in FIG.1G. As with the spinel layer substrate 102, the glass substrate 105 canimprove the quality factor (Q) relative to using a different substrate.Moreover, any suitable principles and advantages of devices, components,and filters disclosed herein that include a spinel substrate can beapplied to devices, components, and filters that include a glasssubstrate.

FIG. 1H is a cross sectional view of a bulk acoustic wave resonator 163.The bulk acoustic wave resonator 163 is generally similar to the bulkacoustic wave resonator 160 illustrated in FIG. 1E, except that the bulkacoustic wave resonator 163 has a frame structure that includes a raisedframe structure 175, a second raised frame structure 177 and a recessedframe structure 179. With the raised frame structures 175 and 177, thebulk acoustic wave resonator 163 can be referred to as a dual raisedframe bulk acoustic wave resonator or a multi-layer raised frame bulkacoustic wave resonator.

The raised frame structure 175 and the second raised frame structure 177overlap with each other in the active region of the bulk acoustic waveresonator 163. A raised frame domain of the bulk acoustic wave device163 is defined by the portion of dual raised frame structure in theactive domain of the bulk acoustic wave device 163. At least a portionof the dual raised frame structure is included in an active region ofthe bulk acoustic wave device 163. The dual raised frame structure canimprove Q significantly due to highly efficient reflection of lateralenergy.

As illustrated in FIG. 1H, the second raised frame structure 177 ispositioned between the piezoelectric layer 150 and the second electrode152. The second raised frame structure 177 is a low acoustic impedancematerial. The low acoustic impedance material has a lower acousticimpedance than the first electrode 128. The low acoustic impedancematerial has a lower acoustic impedance than the second electrode 152.The low acoustic impedance material can have a lower acoustic impedancethan the piezoelectric layer 150. As an example, the second raised framestructure 177 can be a silicon dioxide (SiO₂) layer. Because silicondioxide is already used in a variety of bulk acoustic wave devices, asilicon dioxide second raised frame structure 177 can be relatively easyto manufacture. The second raised frame structure 177 can be a siliconnitride (SiN) layer, a silicon carbide (SiC) layer, or any othersuitable low acoustic impedance layer. The second raised frame structure177 can have a relatively low density. The second raised frame structure177 can extend beyond the active region of the bulk acoustic waveresonator 163. This can be for manufacturability reasons in certaininstances.

The second raised frame structure 177 can reduce an effectiveelectromechanical coupling coefficient (k²) of the raised frame domainof the bulk acoustic wave resonator 163 relative to a similar devicewithout the second raised frame structure 177. This can reduceexcitation strength of a raised frame spurious mode. Moreover, thesecond raised frame structure 177 can contribute to move the frequencyof the raised frame mode relatively far away from the main resonantfrequency of the bulk acoustic wave resonator 163, which can result inno significant effect on a Gamma loss.

A spinel substrate is an example of a ceramic substrate. FIG. 1I is across sectional view of a bulk acoustic wave resonator 164. The bulkacoustic wave resonator 164 is generally similar to the bulk acousticwave resonator 163 illustrated in FIG. 1H, except that the bulk acousticwave resonator 164 includes a ceramic substrate 103 in place of thespinel substrate 102 of the bulk acoustic wave resonator 163. Theceramic substrate 103 can include, for example, polycrystalline spinel(e.g., MgAl₂O₄), co-fired ceramic, or polycrystalline aluminum nitride(AlN). The ceramic substrate 130 can have higher acoustic impedance thanan acoustic impedance of the piezoelectric layer 150. Any suitableprinciples and advantages of devices, components, and filters disclosedherein that include a spinel substrate can be applied to devices,components, and filters that includes a ceramic substrate.

FIG. 1J is a cross sectional view of a bulk acoustic wave resonator 165.The bulk acoustic wave resonator 165 is generally similar to the bulkacoustic wave resonators 163 and 164 illustrated in FIGS. 1H and 1I,respectively, except that the bulk acoustic wave resonator 165 includesa glass substrate 105 in place of the spinel substrate 102 of the bulkacoustic wave resonator 163 and in place of the ceramic substrate 103 ofthe bulk acoustic wave resonator 164. The glass substrate 105 includes anon-crystalline amorphous solid. The glass substrate 105 can include asilicate glass, such as fused quartz glass, lead glass, borosilicateglass, soda-lime silicate glass, aluminosilicate glass, orgermanium-oxide glass. Any suitable principles and advantages ofdevices, components, and filters disclosed herein that include a spinelsubstrate and/or a ceramic substrate can be applied to devices,components, and filters that include a glass substrate.

Embodiments disclosed herein may include the spinel substrate 102.However, the spinel substrate 102 of any of the embodiments disclosedherein can be replaced with another suitable substrate, such as theceramic substrate 103 or the glass substrate 105.

FIG. 2 is a graph of quality factor (Q) and magnitude for a BAWresonator having a spinel substrate according to an embodiment relativeto a BAW resonator with a silicon substrate with a trap rich layer inplace a spinel substrate. As illustrated by the Q curves in FIG. 2, BAWresonators having a spinel substrate can achieve an improved Q relativeto other BAW resonators. FIG. 2 also shows that BAW resonators having aspinel substrate can achieve an improved admittance relative to otherBAW resonators.

FIG. 3 is a cross sectional view of a bulk acoustic wave resonator 300according to an embodiment. The bulk acoustic wave resonator 300 is likethe bulk acoustic wave resonator 160 of FIG. 1E, except that an acousticmirror 304 is included between the spinel substrate 102 and the firstelectrode 128 and the bulk acoustic wave resonator 300 includes arecessed frame structure 306. In some other embodiments (notillustrated), the air gap or air cavity can be omitted from the bulkacoustic wave resonator 300. The illustrated acoustic mirror 304includes a Bragg reflector with alternating low impedance and highimpedance layers 304A and 304B. As an example, the Bragg reflector caninclude alternating silicon dioxide layers 304A and tungsten layers304B. An acoustic mirror with a Bragg reflector can be referred to as asolid acoustic mirror. Any other suitable features of an SMR canalternatively or additionally be implemented in a BAW resonators with aspinel substrate.

FIG. 4 is a cross sectional view of a bulk acoustic wave resonator 400according to an embodiment. The bulk acoustic wave resonator 400 is likethe bulk acoustic wave resonator 300 of FIG. 3, except that the acousticmirrors are positioned differently. In FIG. 4, the BAW resonator 400includes an acoustic mirror 404 disposed below the raised framedstructure. The illustrated acoustic mirror 404 includes a Braggreflectors. As illustrated, the Bragg reflectors are shown on opposingsides of the bulk acoustic wave resonator 400. In the bulk acoustic waveresonator 400, the Bragg reflectors are positioned outside the activedomain. The spinel substrate 102 is included below the first electrode128 in the active domain of the bulk acoustic wave resonator 400. TheBragg reflectors include alternating low impedance and high impedancelayers, such as alternating silicon dioxide layers and tungsten layers.Any other suitable features of an SMR can alternatively or additionallybe implemented in a BAW device.

FIG. 5A is a cross sectional view of a bulk acoustic wave resonator 450according to another embodiment. The bulk acoustic wave resonator 450 islike the bulk acoustic wave resonator 160 of FIG. 1E, except that an aircavity 144 a is formed in a spinel substrate 202 and the bulk acousticwave resonator 450 includes a recessed frame structure 306. The aircavity 144 a can be etched into the spinel substrate 202. Layers (e.g.,a first electrode 128 a, a second electrode 152 a, a piezoelectric layer150 a, a first layer 176 a, a layer 129 a, a passivation layer 126 a,and a passivation layer 174 a) over the spinel substrate 202 aredifferently shaped in FIG. 5A as compared to the layers (e.g., the firstelectrode 128, the second electrode 152, the piezoelectric layer 150,the first layer 176, the layer 129, the passivation layer 126 and thepassivation layer 174) in FIG. 1E. The layers in FIG. 5A can havegenerally similar properties, characteristics, and/or functionalities asthe layers in FIG. 1E.

FIG. 5B is a cross sectional view of a bulk acoustic wave resonator 475according to another embodiment. As illustrated, the bulk acoustic waveresonator 475 includes a piezoelectric layer 150, a first electrode 128,a second electrode 152, a frame structure (e.g., raised frame structures175 and 177 and a recessed frame structure 179), a substrate 205, an aircavity 144, and electrical connection layers that include a first layer176. A layer 129 may be included below the first electrode 128. Thefirst layer 176 can include one or more of ruthenium, molybdenum, orsilicon dioxide. The bulk acoustic wave resonator 475 also includes vias(e.g., a signal via 210 and a thermal via 211), and pads (e.g., a signalpad 207 and a thermal pad 208) that connect to corresponding vias. Thebulk acoustic wave resonator 475 further includes a lid 212 over thesubstrate 205. In some embodiments, the substrate 205 can be a ceramicsubstrate (e.g., a spinel substrate) or a glass substrate.

The signal pad 207 and/or the thermal pad 208 can connect the 475 to anexternal device or substrate (e.g., a printed circuit board (PCB)). Thethermal via 211 and the thermal pad 208 can provide the bulk acousticwave resonator 475 a better thermal conductivity than a similar bulkacoustic wave resonator without the thermal via and/or the thermal pad.

In some instances, the principles and advantages of thermal dissipationin the bulk acoustic wave resonator 475 can be applied to a solidmounted resonator (SMR). In such instances a thermal via can extendthrough a solid acoustic mirror.

Various types of acoustic wave resonators and/or devices can beimplemented on a common substrate (e.g., a spinel substrate, a ceramicsubstrate, or a glass substrate). Accordingly, an acoustic wavecomponent can include different types of acoustic wave resonators and/ordevices on a common spinel substrate and within a common package. Forexample, an FBAR and a SAW resonator can be implemented on a commonspinel substrate. In some instances, an FBAR and a temperaturecompensated SAW resonator can be implemented on a common spinelsubstrate. As another example, an FBAR and an SMR can be implemented ona common spinel substrate. As another example, a BAW resonator and aLamb wave resonator can be implemented on a common spinel substrate. Asone more example, a BAW resonator and a boundary wave resonator can beimplemented on a common spinel substrate. Any suitable combination offeatures of the embodiments disclosed herein with different types ofacoustic wave resonators on a common spinel substrate can be implementedwith each other. Also, any suitable combination of features of theembodiments disclosed herein with different types of acoustic waveresonators on a common ceramic substrate and/or a common glass substratecan be implemented with each other.

FIG. 6A shows an example cross section 500 of a BAW resonator 160 and aSAW device 520 on a common substrate 302. BAW resonators in accordancewith any suitable principles and advantages disclosed herein can beimplemented on the same substrate as a SAW device and/or resonator. TheSAW device 520 can be a SAW resonator. Any suitable combination of theBAW and SAW resonators can be formed on a common substrate 203. Forexample, as illustrated, the BAW resonator 160, which is illustrated asan FBAR, may be positioned laterally from the SAW device 520 on thecommon substrate 302. The SAW device 520 includes a piezoelectric layer521 on the common substrate 302 and an interdigital transducer electrode522 on the piezoelectric layer 521. The common substrate 302 can be aceramic substrate (e.g., a spinel substrate) or a glass substrate. Thepiezoelectric layer 521 can be a lithium tantalate (LT) layer or alithium niobate (LN) layer, for example. In some instances, thepiezoelectric layer 521 of the SAW device 520 can be the same materialas the piezoelectric layer 150 of the BAW resonator 160. For example,the piezoelectric layer 521 of the SAW device 520 can be an aluminumnitride layer and the piezoelectric layer 150 of the BAW resonator 160can be an aluminum nitride layer.

In the acoustic wave component of FIG. 6A, a first portion 501 of thesubstrate 302 can be considered part of the BAW resonator 160 and asecond portion 502 of the common substrate 302 can be considered part ofthe SAW device 520. The common substrate 302 can be part of a multilayerpiezoelectric substrate of the SAW device 520. A dispersion adjustmentlayer can be included between the piezoelectric layer 521 of the SAWdevice 520 and the common substrate 302 in certain applications.Although not illustrated in FIG. 6A, the SAW device 520 can be atemperature compensated SAW device with a temperature compensation layerover the interdigital transducer electrode. The temperature compensationlayer can be a silicon dioxide layer, for example.

FIG. 6B shows an example embodiment of an acoustic wave component 600including a SAW device 520 formed in the air cavity of a BAW resonator510. The air cavity 144 of the BAW resonator 510 can have a sizesufficient to accommodate the SAW device 520. Accordingly, the BAWresonator 510 can have a taller air cavity than the BAW resonator 160 incertain applications. The electrodes and piezoelectric layer of the BAWresonator 510 can serve as a cap for the SAW device 520. Thepiezoelectric layer 521 of the SAW device 520 may be in direct contactwith the common substrate 302. Alternatively, an intervening layer canbe included between the piezoelectric layer 521 of the SAW device 520and the common substrate 302.

FIG. 7A illustrates an example embodiment of an acoustic wave component700 that includes a BAW resonator 160, a first SAW device 720, and asecond SAW device 725. The illustrated acoustic wave devices 160, 720,and 725 are formed on a common substrate 302. In some instances, one ormore of the acoustic wave devices may be on different surfaces of thecommon substrate 302. For example, acoustic wave devices can bepositioned on opposing sides of the common substrate 302.

FIG. 7B is a schematic diagram of a duplexer that includes a transmitfilter 750, a receive filter 760, a transmit port 752, a receive port762, and an antenna port 745. The illustrated duplexer is a hybridduplexer that includes BAW resonators and SAW resonators. Byimplementing BAW and SAW resonators of a duplexer on a common spinelsubstrate, an electrical connection line can be shorter. This canenhance performance of the duplexer and/or reduce mismatches that canresult from relatively long connection lines. The transmit filter 750includes BAW resonators with relatively high durability and SAWresonators that are relatively low cost. The BAW resonators 730 of thetransmit filter 750 are coupled to the antenna node 745 by way of a SAWresonator. This can result in a harmonic improvement for the transmitfilter 750.

The transmit filter 750 is coupled to the receive filter 760 at anantenna node. The duplexer of FIG. 7B can be implemented using acousticwave resonators shown in FIG. 7A. For example, the transmit filter 750can include BAW resonators 730 and SAW resonators 740. Some or all ofthe BAW resonators 730 can be implemented in accordance with anysuitable principles and advantages of a BAW resonator with a spinelsubstrate disclosed herein. For instance, the BAW resonator 734 can beimplemented by the BAW resonator 160 of FIG. 7A. Some or all of the SAWresonators 740 can be implemented on a common spinel substrate with oneor more of the BAW resonators 730. For example, the one of the SAWresonators 740 can be implemented by the SAW resonator 720 of FIG. 7A.The receive filter 760 can be implemented by SAW resonators, in whichone or more of the SAW resonators can be implemented on a common spinelsubstrate with one or more of the BAW resonators 730 and/or one or moreof the SAW resonators 740. As an example, the SAW resonator 764 can beimplemented by the SAW resonator 725 of FIG. 7A.

The illustrated transmit filter 750 is arranged to filter a radiofrequency signal received at a transmit port 752 and provide a filteredoutput signal to the antenna port 745. A series inductor can be coupledbetween a transmit port 752 and the acoustic wave resonators of thetransmit filter 750. A shunt inductor can be connected to the antennanode at which the transmit filter 750 is coupled to the receive filter760. The transmit filter and the receive filter are both acoustic waveladder filters in the duplexer shown in FIG. 7B. The transmit filter 750can be a band pass filter. Any suitable number of series BAW resonatorsand shunt BAW resonators can be included in a transmit filter 750. Thereceive filter 760 may be a band pass filter. The illustrated receivefilter 760 is arranged to filter a radio frequency signal received at anantenna port 745 and provide a filtered output signal to a receive port762. Any suitable number of series resonators and shunt resonators canbe included in the receive filter 760.

FIG. 8 is a schematic diagram of a duplexer 800 according to anembodiment. The duplexer 800 of FIG. 8 is like the duplexer of FIG. 7except that the duplexer 800 includes a loop circuits. As illustrated,the duplexer 800 includes a transmit loop circuit 835 and a receive loopcircuit 865. Some or all of the acoustic wave devices of the duplexer800 can be implemented on a common spinel substrate.

The transmit loop circuit 835 is coupled to the transmit filter 750. Thetransmit loop circuit 835 can be coupled to an input resonator and anoutput resonator of the transmit filter 750. In some other instances,the loop circuit 835 can be coupled to a different node of the transmitfilter 750 than illustrated. The loop circuit 835 can apply a signalhaving approximately the same amplitude and an opposite phase to asignal component to be canceled. Accordingly, the loop circuit 835 isconfigured to generate an anti-phase signal to a target signal at aparticular frequency. The transmit loop circuit 835 can include SAWdevices coupled to the transmit filter 750 by respective capacitors. TheSAW devices of the loop circuit 835 can be implemented on a commonspinel substrate as some or all of the BAW resonators 730 of thetransmit filter 750. For example, a SAW device of the transmit loopcircuit 835 can correspond to the SAW device 720 of FIG. 7A and a BAWresonator of the BAW resonators 730 can correspond to the BAW resonator160 of FIG. 7A. The transmit loop circuit 835 can be implemented inaccordance with any suitable principles and advantages described in U.S.Pat. Nos. 9,246,533 and/or 9,520,857, the disclosures of these patentsare hereby incorporated by reference in their entireties herein.

The receive loop circuit 865 is coupled to the receive filter 760. Thereceive loop circuit 865 can generally implement any suitable featuresof the transmit loop circuit 835 except on the receive side. The SAWdevices of the receive loop circuit 865 can be implemented on a commonspinel substrate as some or all of the BAW resonators 730 of thetransmit filter 750. For example, a SAW device of the receive loopcircuit 865 can correspond to the SAW device 725 of FIG. 7A and a BAWresonator of the BAW resonators 730 can correspond to the BAW resonator160 of FIG. 7A.

Although FIGS. 7B and 8 illustrate duplexers, any suitable principlesand advantages discussed herein (e.g., with reference to FIG. 7B and/orFIG. 8) can be implemented in any other multiplexer that includes aplurality of filters coupled to a common node (e.g., a quadplexer, ahexaplexer, an octoplexer, or the like). Similarly, although FIG. 8illustrates a duplexer with a transmit filter and a receive filter, anysuitable principles and advantages of FIG. 8 and/or other embodimentsdisclosed herein can be implemented in a transmit filter and/or areceive filter. For example, FIG. 9 illustrates a transmit filter 750with a loop circuit 835 according to an embodiment. As another example,FIG. 10 illustrates a receive filter 760 with a loop circuit 865according to an embodiment.

The acoustic wave resonators with a spinel substrate disclosed hereincan be implemented in a variety of packaged modules. Some examplepackaged modules will now be discussed in which any suitable principlesand advantages of the acoustic wave devices disclosed herein can beimplemented. The example packaged modules can include a package thatencloses the illustrated circuit elements. The illustrated circuitelements can be disposed on a common packaging substrate. The packagingsubstrate can be a laminate substrate, for example. FIGS. 11 and 12 areschematic block diagrams of illustrative packaged modules according tocertain embodiments. Any suitable combination of features of thesemodules can be implemented with each other. While duplexers areillustrated in the example packaged module of FIG. 12, any othersuitable multiplexer that includes a plurality of acoustic wave filterscoupled to a common node can be implemented instead of one or moreduplexers. For example, a quadplexer can be implemented in certainapplications. Alternatively or additionally, one or more filters of apackaged module can be arranged as a transmit filter or a receive filterthat is not included in a multiplexer.

An acoustic wave device (e.g., the BAW resonator or the SAW resonator)including any suitable combination of features disclosed herein can beincluded in a filter arranged to filter a radio frequency signal in afifth generation (5G) New Radio (NR) operating band within FrequencyRange 1 (FR1). A filter arranged to filter a radio frequency signal in a5G NR operating band can include one or more BAW resonators and/or SAWdevices disclosed herein. FR1 can be from 410 MHz to 7.125 GHz, forexample, as specified in a current 5G NR specification.

A filter including one or more BAW resonators disclosed herein canachieve better harmonic performance (e.g., lower harmonic distortionand/or less intermodulation distortion) than some other BAW resonatorsin 5G applications. Ceramic and/or glass substrates disclosed herein cancontribute to better harmonic performance than silicon substrates,particularly at relative high power and/or relatively high operatingtemperature. For example, ceramic and/or glass substrates can improveharmonic performance in relative high peak power operations in 5Gapplications and/or in operations with a relatively high average power(such as with relatively high time division duplexing transmit dutycycles) in 5G applications.

One or more acoustic wave devices in accordance with any suitableprinciples and advantages disclosed herein can be included in a filterarranged to filter a radio frequency signal in a 4G LTE operating band.One or more acoustic wave devices in accordance with any suitableprinciples and advantages disclosed herein can be included in a filterarranged to filter a radio frequency signal in a filter having apassband that includes a 4G LTE operating band and a 5G NR operatingband.

FIG. 11 is a schematic diagram of a radio frequency module 1100 thatincludes an acoustic wave component 1102 according to an embodiment. Theillustrated radio frequency module 1100 includes the acoustic wavecomponent 1102 and other circuitry 1103. The acoustic wave component1102 can include one or more acoustic wave resonators and/or deviceswith a spinel substrate in accordance with any suitable combination offeatures of the acoustic wave resonators disclosed herein. The acousticwave component 1102 can include an acoustic wave die that includesacoustic wave resonator and/or devices s. For example, the acoustic wavecomponent 1102 can include a BAW die with a spinel substrate. As anotherexample, the acoustic wave component 1102 can include one or more BAWresonators and one or more SAW devices on a common spinel substrate.

The acoustic wave component 1102 shown in FIG. 11 includes a filter 1104and terminals 1105A and 1105B. The filter 1104 includes acoustic waveresonators. One or more of the acoustic wave resonators can beimplemented in accordance with any suitable principles and advantages ofthe acoustic wave resonators with a spinel substrate disclosed herein.The filter 1104 can include one or more BAW resonators arranged tofilter radio frequency signals in an operating band in a range from 3.5GHz to 13 GHz, 5 GHz to 10 GHz, or any range disclosed herein. Theterminals 1105A and 1104B can serve, for example, as an input contactand an output contact. The acoustic wave component 1102 and the othercircuitry 1103 are on a common packaging substrate 1106 in FIG. 11. Thepackage substrate 1106 can be a laminate substrate. The terminals 1105Aand 1105B can be electrically connected to contacts 1107A and 1107B,respectively, on the packaging substrate 1106 by way of electricalconnectors 1108A and 1108B, respectively. The electrical connectors1108A and 1108B can be bumps or wire bonds, for example.

The other circuitry 1103 can include any suitable additional circuitry.For example, the other circuitry can include one or more one or morepower amplifiers, one or more radio frequency switches, one or moreadditional filters, one or more low noise amplifiers, one or more RFcouplers, one or more delay lines, one or more phase shifters, the like,or any suitable combination thereof. The radio frequency module 1100 caninclude one or more packaging structures to, for example, provideprotection and/or facilitate easier handling of the radio frequencymodule 1100. Such a packaging structure can include an overmoldstructure formed over the packaging substrate 1100. The overmoldstructure can encapsulate some or all of the components of the radiofrequency module 1100.

FIG. 12 is a schematic diagram of a radio frequency module 1210 thatincludes an acoustic wave component according to an embodiment. Asillustrated, the radio frequency module 1210 includes duplexers 1212A to1212N that include respective transmit filters 1213A1 to 1213N1 andrespective receive filters 1213A2 to 1213N2, a power amplifier 1214, aselect switch 1215, and an antenna switch 1216. The radio frequencymodule 1210 can include a package that encloses the illustratedelements. The illustrated elements can be disposed on a common packagingsubstrate 1206. The packaging substrate 1206 can be a laminatesubstrate, for example. A radio frequency module that includes a poweramplifier can be referred to as a power amplifier module. A radiofrequency module can include a subset of the elements illustrated inFIG. 12 and/or additional elements. The radio frequency module 1210 mayinclude any one of the acoustic wave devices with a spinel substrates inaccordance with any suitable principles and advantages disclosed herein.

The duplexers 1212A to 1212N can each include two acoustic wave filterscoupled to a common node. For example, the two acoustic wave filters canbe a transmit filter and a receive filter, for example, as describedwith reference to FIGS. 7B and/or 8. As illustrated, the transmit filterand the receive filter can each be a band pass filter arranged to filtera radio frequency signal. One or more of the transmit filters 1213A1 to1213N1 can include one or more acoustic wave resonators with a spinelsubstrate in accordance with any suitable principles and advantagesdisclosed herein. Similarly, one or more of the receive filters 1213A2to 1213N2 can include one or more acoustic wave resonators with a spinelsubstrate in accordance with any suitable principles and advantagesdisclosed herein. Although FIG. 12 illustrates duplexers, any suitableprinciples and advantages disclosed herein can be implemented in othermultiplexers (e.g., quadplexers, hexaplexers, octoplexers, etc.) and/orin switch-plexers.

The power amplifier 1214 can amplify a radio frequency signal. Theillustrated switch 1215 is a multi-throw radio frequency switch. Theswitch 1215 can electrically couple an output of the power amplifier1214 to a selected transmit filter of the transmit filters 1213A1 to1213N1. In some instances, the switch 1215 can electrically connect theoutput of the power amplifier 1214 to more than one of the transmitfilters 1213A1 to 1213N1. The antenna switch 1216 can selectively couplea signal from one or more of the duplexers 1212A to 1212N to an antennaport ANT. The duplexers 1212A to 1212N can be associated with differentfrequency bands and/or different modes of operation (e.g., differentpower modes, different signaling modes, etc.).

FIG. 13A is a schematic diagram of a wireless communication 1020 devicethat includes filters 1023 in a radio frequency front end 1022 accordingto an embodiment. The filters 1023 may be implemented on one or morespinel substrates as described herein. The filters 1023 can include oneor more wave resonators with a spinel substrate in accordance with anysuitable principles and advantages discussed herein. The wirelesscommunication device 1020 can be any suitable wireless communicationdevice. For instance, a wireless communication device 1020 can be amobile phone, such as a smart phone. As illustrated, the wirelesscommunication device 1020 includes an antenna 1021, an RF front end1022, a transceiver 1024, a processor 1025, a memory 1026, and a userinterface 1027. The antenna 1021 can transmit RF signals provided by theRF front end 1022. Such RF signals can include carrier aggregationsignals. The antenna 1021 can receive RF signals and provide thereceived RF signals to the RF front end 1022 for processing.

The RF front end 1022 can include one or more power amplifiers, one ormore low noise amplifiers, one or more RF switches, one or more receivefilters, one or more transmit filters, one or more duplex filters, oneor more multiplexers, one or more frequency multiplexing circuits, thelike, or any suitable combination thereof. The RF front end 1022 cantransmit and receive RF signals associated with any suitablecommunication standards. The filters 1023 can include one or moreacoustic wave resonators on a spinel substrate that include any suitablecombination of features discussed with reference to any embodimentsdiscussed above.

The transceiver 1024 can provide RF signals to the RF front end 1022 foramplification and/or other processing. The transceiver 1024 can alsoprocess an RF signal provided by a low noise amplifier of the RF frontend 1022. The transceiver 1024 is in communication with the processor1025. The processor 1025 can be a baseband processor. The processor 1025can provide any suitable base band processing functions for the wirelesscommunication device 1020. The memory 1026 can be accessed by theprocessor 1025. The memory 1026 can store any suitable data for thewireless communication device 1020. The user interface 1027 can be anysuitable user interface, such as a display with touch screencapabilities.

FIG. 13B is a schematic diagram of a wireless communication device 1330that includes filters 1023 in a radio frequency front end 1022 andsecond filters 1333 in a diversity receive module 1332. The secondfilters 1023 can include one or more acoustic wave resonators on spinelsubstrate in accordance with any suitable principles and advantagesdisclosed herein. The wireless communication device 1330 is like thewireless communication device 1020 of FIG. 13A, except that the wirelesscommunication device 1330 also includes diversity receive features. Asillustrated in FIG. 13B, the wireless communication device 1330 includesa diversity antenna 1331, a diversity module 1332 configured to processsignals received by the diversity antenna 1331 and including filters1333, and a transceiver 1334 in communication with both the radiofrequency front end 1022 and the diversity receive module 1332. Thefilters 1333 can include one or more acoustic wave resonators with aspinel substrate that include any suitable combination of featuresdiscussed with reference to any embodiments discussed above.

Any of the embodiments described above can be implemented in mobiledevices such as cellular handsets. The principles and advantages of theembodiments can be used for any systems or apparatus, such as any uplinkcellular device, that could benefit from any of the embodimentsdescribed herein. The teachings herein are applicable to a variety ofsystems. Although this disclosure includes some example embodiments, theteachings described herein can be applied to a variety of structures.Any of the principles and advantages discussed herein can be implementedin association with RF circuits configured to process signals having afrequency in a range from about 30 kHz to 300 GHz, such as a frequencyin a range from about 450 MHz to 8.5 GHz.

Aspects of this disclosure can be implemented in various electronicdevices. Examples of the electronic devices can include, but are notlimited to, consumer electronic products, parts of the consumerelectronic products such as die and/or acoustic wave filter assembliesand/or packaged radio frequency modules, uplink wireless communicationdevices, wireless communication infrastructure, electronic testequipment, etc. Examples of the electronic devices can include, but arenot limited to, a mobile phone such as a smart phone, a wearablecomputing device such as a smart watch or an ear piece, a telephone, atelevision, a computer monitor, a computer, a modem, a hand-heldcomputer, a laptop computer, a tablet computer, a personal digitalassistant (PDA), a microwave, a refrigerator, an automobile, a stereosystem, a DVD player, a CD player, a digital music player such as an MP3player, a radio, a camcorder, a camera, a digital camera, a portablememory chip, a washer, a dryer, a washer/dryer, a peripheral device, awrist watch, a clock, etc. Further, the electronic devices can includeunfinished products.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,”“include,” “including” and the like are to be construed in an inclusivesense, as opposed to an exclusive or exhaustive sense; that is to say,in the sense of “including, but not limited to.” The word “coupled”, asgenerally used herein, refers to two or more elements that may be eitherdirectly connected, or connected by way of one or more intermediateelements. Likewise, the word “connected”, as generally used herein,refers to two or more elements that may be either directly connected, orconnected by way of one or more intermediate elements. Additionally, thewords “herein,” “above,” “below,” and words of similar import, when usedin this application, shall refer to this application as a whole and notto any particular portions of this application. Where the contextpermits, words in the above Detailed Description using the singular orplural number may also include the plural or singular numberrespectively. The word “or” in reference to a list of two or more items,that word covers all of the following interpretations of the word: anyof the items in the list, all of the items in the list, and anycombination of the items in the list.

Moreover, conditional language used herein, such as, among others,“can,” “could,” “might,” “may,” “e.g.,” “for example,” “such as” and thelike, unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or states. Thus, such conditional language is notgenerally intended to imply that features, elements and/or states are inany way required for one or more embodiments.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the disclosure. Indeed, the novel apparatus, methods, andsystems described herein may be embodied in a variety of other forms;furthermore, various omissions, substitutions and changes in the form ofthe methods and systems described herein may be made without departingfrom the spirit of the disclosure. For example, while blocks arepresented in a given arrangement, alternative embodiments may performsimilar functionalities with different components and/or circuittopologies, and some blocks may be deleted, moved, added, subdivided,combined, and/or modified. Each of these blocks may be implemented in avariety of different ways. Any suitable combination of the elements andacts of the various embodiments described above can be combined toprovide further embodiments. The accompanying claims and theirequivalents are intended to cover such forms or modifications as wouldfall within the scope and spirit of the disclosure.

What is claimed is:
 1. An acoustic wave component comprising: a bulkacoustic wave resonator including a first portion of a ceramicsubstrate, a first piezoelectric layer on the ceramic substrate, andelectrodes on opposing sides of the first piezoelectric layer; and asurface acoustic wave device including a second portion of the ceramicsubstrate, a second piezoelectric layer on the ceramic substrate, and aninterdigital transducer electrode on the second piezoelectric layer. 2.The acoustic wave component of claim 1 wherein the ceramic substrate isa spinel substrate.
 3. The acoustic wave component of claim 1 whereinthe bulk acoustic wave resonator includes a frame structure along anedge of an active region of the bulk acoustic wave resonator.
 4. Theacoustic wave component of claim 1 wherein the bulk acoustic waveresonator includes a passivation layer between the ceramic substrate andan electrode of the electrodes that is closest to the ceramic substrate.5. The acoustic wave component of claim 1 wherein the bulk acoustic waveresonator is a film bulk acoustic wave resonator.
 6. The acoustic wavecomponent of claim 1 wherein the bulk acoustic wave resonator includesan air cavity between the ceramic substrate and an electrode of theelectrodes.
 7. The acoustic wave component of claim 6 wherein thesurface acoustic wave device is disposed in the air cavity.
 8. Theacoustic wave component of claim 1 wherein the bulk acoustic waveresonator is positioned laterally from the surface acoustic wave device.9. The acoustic wave component of claim 1 further comprising a receivefilter and a transmit filter coupled to each other at a common node, thereceive filter including the surface acoustic wave device and thetransmit filter including the bulk acoustic wave resonator.
 10. Theacoustic wave component of claim 9 wherein the transmit filter furtherincludes another surface acoustic wave device that includes a thirdportion of the ceramic substrate.
 11. The acoustic wave component ofclaim 9 wherein the transmit filter further includes a loop circuitconfigured to generate an anti-phase signal to a target signal at aparticular frequency, and the loop circuit includes another surfaceacoustic wave device that includes a third portion of the ceramicsubstrate.
 12. The acoustic wave component of claim 9 wherein thereceive filter further includes a loop circuit configured to generate ananti-phase signal to a target signal at a particular frequency, and theloop circuit includes another surface acoustic wave resonator thatincludes a third portion of the ceramic substrate.
 13. A multiplexercomprising: a first filter including a bulk acoustic wave resonator, thebulk acoustic wave resonator including a first portion of a ceramicsubstrate, a first piezoelectric layer on the ceramic substrate, andelectrodes on opposing sides of the first piezoelectric layer; and asecond filter coupled to the first filter at a common node, the secondfilter including a surface acoustic wave device, and the surfaceacoustic wave device including a second portion of the ceramicsubstrate, a second piezoelectric layer on the ceramic substrate, and aninterdigital transducer electrode on the second piezoelectric layer. 14.The multiplexer of claim 13 wherein the ceramic substrate is a spinelsubstrate.
 15. An acoustic wave component comprising: a film bulkacoustic wave resonator including a first portion of a ceramicsubstrate, a piezoelectric layer on the ceramic substrate, andelectrodes on opposing sides of the piezoelectric layer; and anothertype of acoustic wave resonator including a second portion of theceramic substrate.
 16. The acoustic wave component of claim 15 whereinthe ceramic substrate is a spinel substrate.
 17. The acoustic wavecomponent of claim 15 wherein the other type of acoustic wave resonatoris a surface acoustic wave resonator.
 18. The acoustic wave component ofclaim 15 wherein the other type of acoustic wave resonator is a solidlymounted resonator.
 19. The acoustic wave component of claim 15 whereinthe first portion of the ceramic substrate is laterally positioned fromthe second portion of the ceramic substrate.
 20. The acoustic wavecomponent of claim 15 wherein the first portion of the ceramic substratesubstantially overlaps with the second portion of the ceramic substrate.